Using Polystyrene to Insulate the Crawlspace Walls

The crawlspace walls are only two cinder blocks high.  I measured them carefully and was delighted to see that they were 16″ on the button.  This would allow me to purchase 48×96 sheets and cut them up without any waste.

I bought three sheets (at $45+ each) and figured that would be a good start.

They have sat on the front porch for a few weeks now, but with the recent delay in paneling the kitchen area, I figured now would be a good time to go down into the crawlspace and deal with this situation.

First I spent an hour or two listening to the latest Canadaland podcast while using my circular saw to cut the foam into strips.  I’m really enjoying Jesse Brown’s critique of Canadian media, although he sometimes uses salty language that I’m personally not hip enough to feel comfortable with.

Bringing them inside, I realized that there was going to be a long-term issue with tiny foam balls sticking to everything in the cabin.  Oh well, I prepared as best I could.  I wore coveralls and lay down some carpets and blankets and tried to get the sheets of insulation down into the crawlspace as directly as possible.

Sheets all cut perfectly to size!

Mmmm, roasted peanuts on the table to give me the energy I need to complete this task!

Of course, once under the cabin, I realized that where I had measured was the only spot where the height was 16 inches.  Everywhere else was about 15 and 5/8.  Sigh.

Does anyone need a stack of 48″ x 1/2″ foam strips?

I brought the saw down into the crawlspace with me and proceeded to rip about a half inch off of all the sheets.  This made a huge mess in the crawlspace, which in turn stuck to me (thank you static electricity!), which in turn came unstuck just long enough to find other homes throughout the cabin.

Finding this stuff everywhere now!

In any case, I was able to friction fit the foam around the outer perimeter of the cabin.  I took the time to cut smaller pieces where they fit over the vents.  I will pull those out in the spring and replace them in the fall.  At least, that’s my plan.

I also had to skip spots (for now) where my water lines and electrical lines entered the floor out close to the cinder blocks.  Once I have more of the electrical and water line work finished in the kitchen, I intend to use expanding spray foam to cover up those sorts of gaps.

It’s a bit off-putting to not be able to put an exact degree figure on just how much difference insulating an area like this will make – but I have to convince myself that it must make SOME difference!

Now that I’m back upstairs and my lovely family has returned from a homeschooling trip to the city, I’m enjoying a chance to sit quietly and enter this latest update.  But in an attempt to play the sympathy card – here’s the conditions I had to work under, and the (nearly) finished project (I still need another half sheet or so to complete the perimeter, and of course, do the spray foaming…)

Crawling over and around these pipes and wires really challenges my patience and flexibility!

Dark over on that side of the cabin – but I have almost 3′ of height there – a real luxury!

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